I don't own a 'range bag'. Never saw the need for one. for what they want for one big enough to suit my needs, I could get a non specifically designed dufflebag or back pack and have cash to spare to spend on something useful like powder, primers and shot or simply get some store bought ammo. All I need is a way to carry my gear from the house to the truck, from the truck to the bench or range table and back. I've got 2 different bags I use for shooting. I use a big dufflebag that I picked up from either CTD or one of the other discount outdoor/gun accessory places really cheap a long time ago. It's big enough that if I fill it completely up, I can't pick it up, so it's big enough to carry a few hundred rounds of ammo, hearing protection, targets, several pistols in rugs or hard cases, .... with room to spare.
For cap and ball shooting, I have an old cheapo backpack that I use. The large center compartment is big enough to carry even my 1st Model Dragoon in a hard case and the outer zippered pockets are great for keeping powder, ball, caps and cleaning equipment handy but separated. (I'm sorta picky about keeping caps and powder together).